(A) Field of the Invention
The present invention relates to an integrated peripheral component interconnect (PCI) interface card and its bus system, particularly to a PCI interface card that integrates at least two bus masters and the bus system thereof.
(B) Description of Related Art
PCI slots have become an industrial standard of personal computers, and acts as a conjunction channel for high performance PCI interfaces cards and processors. The PCI interface card, such as sound card, modem, display card, and TV tune card, etc. achieves 100 MB data exchange with the processor by being inserted into the PCI slot of 32-bit bus width.
On a PCI interface card, sometimes there might be more than two bus masters, and in such case a PCI bridge is needed to designate a bus authority between these bus masters, and distribute I/O ports and the start address and size of the memory.
The prior art PCI bus system is illustrated in FIG. 1. The motherboard end of personal computers comprises a PCI host controller 11, such as the north bridge in a chipset. The PCI host controller 11 can be used in arbitrating which one of the PCI interface cards installed in the PCI slots can obtain the bus authority. The interface card end comprises three interface cards, which are first PCI interface card 12, second PCI interface card 13 and third PCI interface card 14, wherein the first PCI interface card 12 comprises a first bus master 121, a second bus master 122 and a PCI bridge 16, and the second PCI interface card 13 and third PCI interface card 14 comprise third bus master 131 and fourth bus master 141, respectively. As the first PCI interface card 12 comprises two bus masters, a PCI Bridge 16 should be added to designate a bus authority.
The drawbacks of the using PCI bridge 16 are as follows:                1. the framework of the drive software needs to be changed;        2. the overall performance is lowered; and        3. the overall costs are higher.        
With the popularity of PCI interface cards that comprise multiple bus masters, it becomes a prominent issue to figure out how to raise the performance of the interface cards and lower their costs.